The primary objective of the proposed investigation is to determine the role of familial aggregation of cancer and/or congenital malformations in the etiology of childhood brain tumors. The investigators will also determine whether such familial aggregation predisposes to (or interacts with) childhood brain tumors when the child also has environmental exposures, such as parental occupational exposures and prenatal exposure to maternal illnesses drugs or smoking. The investigators propose to analyze data that were previously collected with funding from the American Cancer Society and the National Institute for Occupational Safety and Health. The cases were identified from eight of the population-based Surveillance, Epidemiology and End Results tumor registries in the United States and consist of 361 children under 17 years of age with histologically confirmed brain tumors. Three controls per case were identified by random-digit-dialing, matching to cases on age, sex, maternal racial/ethnic group and telephone prefix. Parents of cases and controls were interviewed in-person in their homes regarding personal and family medical history (including cancer and congenital malformations), parental occupation, prenatal exposures and other risk factors for brain tumors in children. In the present analysis, odds ratios will be used to estimate the relative risk for familial aggregation as well as for occupational and other exposures stratified by family history of cancer or congenital malformations. A number of analyses and manuscripts have resulted from the original study, most of which involve the relationship of parental occupational exposures to the risk of brain tumors in children. Funding is now requested to conduct additional analyses on familial aggregation of cancer and congenital malformations, the interaction of familial aggregation with parental occupational exposures and the role of other risk factors (particularly maternal prenatal illnesses an medications) in the risk of brain tumors in children.